1ad218f3af
As our implementation of MCP411 nears completion and we begin to solicit testing, it's no longer reasonable to expect testers to type or remember `BikeshedIntrinsicFrom`. The name degrades the ease-of-reading of documentation, and the overall experience of using compiler safe transmute. Tentatively, we'll instead adopt `TransmuteFrom`. This name seems to be the one most likely to be stabilized, after discussion on Zulip [1]. We may want to revisit the ordering of `Src` and `Dst` before stabilization, at which point we'd likely consider `TransmuteInto` or `Transmute`. [1] https://rust-lang.zulipchat.com/#narrow/stream/216762-project-safe-transmute/topic/What.20should.20.60BikeshedIntrinsicFrom.60.20be.20named.3F
84 lines
2.2 KiB
Rust
84 lines
2.2 KiB
Rust
//@ check-pass
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//! A struct must have a well-defined layout to participate in a transmutation.
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#![crate_type = "lib"]
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#![feature(transmutability)]
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#![allow(dead_code, incomplete_features, non_camel_case_types)]
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mod assert {
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use std::mem::{Assume, TransmuteFrom};
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pub fn is_maybe_transmutable<Src, Dst>()
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where
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Dst: TransmuteFrom<Src, {
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Assume {
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alignment: true,
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lifetimes: true,
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safety: true,
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validity: true,
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}
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}>
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{}
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}
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fn should_accept_repr_rust()
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{
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fn unit() {
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struct repr_rust;
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assert::is_maybe_transmutable::<repr_rust, ()>();
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assert::is_maybe_transmutable::<u128, repr_rust>();
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}
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fn tuple() {
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struct repr_rust();
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assert::is_maybe_transmutable::<repr_rust, ()>();
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assert::is_maybe_transmutable::<u128, repr_rust>();
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}
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fn braces() {
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struct repr_rust{}
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assert::is_maybe_transmutable::<repr_rust, ()>();
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assert::is_maybe_transmutable::<u128, repr_rust>();
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}
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fn aligned() {
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#[repr(align(1))] struct repr_rust{}
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assert::is_maybe_transmutable::<repr_rust, ()>();
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assert::is_maybe_transmutable::<u128, repr_rust>();
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}
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fn packed() {
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#[repr(packed)] struct repr_rust{}
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assert::is_maybe_transmutable::<repr_rust, ()>();
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assert::is_maybe_transmutable::<u128, repr_rust>();
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}
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fn nested() {
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struct repr_rust;
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#[repr(C)] struct repr_c(repr_rust);
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assert::is_maybe_transmutable::<repr_c, ()>();
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assert::is_maybe_transmutable::<u128, repr_c>();
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}
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}
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fn should_accept_repr_c()
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{
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fn unit() {
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#[repr(C)] struct repr_c;
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assert::is_maybe_transmutable::<repr_c, ()>();
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assert::is_maybe_transmutable::<i128, repr_c>();
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}
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fn tuple() {
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#[repr(C)] struct repr_c();
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assert::is_maybe_transmutable::<repr_c, ()>();
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assert::is_maybe_transmutable::<i128, repr_c>();
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}
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fn braces() {
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#[repr(C)] struct repr_c{}
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assert::is_maybe_transmutable::<repr_c, ()>();
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assert::is_maybe_transmutable::<i128, repr_c>();
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}
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}
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